This invention concerns ventilations devices for the simultaneous ventilation and exhausting of rooms, particularly with the recovery of heat from the air flow. Such a ventilating device may have a box-shaped housing to be mounted on a room wall. Such a device is connected through channels leading to outside air for the ventilation and exhaust media flows, respectively. Within the housing two flow routes or currents are developed separate from one another. They each are provided with an inlet and an outlet, the inlets being arranged on opposite walls of the device. In order to carry out active movement of the ventilating media both flow routes are provided with a radial blower and a blower wheel inside the housing, preferably as a single blower wheel divided by a radial separating wall into two independent ventilation media moving means. These means project into each of the flow routes somewhere near its respective inlet opening. The exhaust inlet opening in the device is formed on the front wall facing the room while the outlet for the ventilating air from the device is likewise usually placed in the same front wall facing the room.
Ventilation devices of this structure which operate in this manner are disclosed in German Patent 3,017,431 and German Patent 3,111,360. These devices, especially the latter device, have proved themselves to be quite useful in practical applications.
In these known ventilation devices high efficiency of heat recovery depends on a number of factors. Initially, the radial blower is constructed of a blower wheel consisting of two halves, each in a respective portion of a joint chamber which is used by both exhaust and ventilation flow routes. This chamber for both flow routes is defined within the housing by an insertion body which spirally embraces the perimeter of the blower wheel and is spaced from it. At a longitudinal distance from this chamber the two flow routes merge into a heat exchanger element which is formed in a cross-current construction into an odd number of longitudinal sections following one another in a convoluted pattern in the flow through direction. Between each two right-angled, successive exchange areas formed by stacks of lamellae or plates there is a lamellae-free or plate-free area. The lamellae or plate stack adjacent to the blower wheel is configured with a vertical edge which effects the initial separation of the two flow routes and is in the same plane as the separating wall of the blower wheel. The end body which separates the two end chambers from one another consists of a level separating wall which lies in the same plane as the vertical edge of the lamellae or plate stack; this effects the final separation of the two flow routes of the lamellae or plate stack at a distance from the radial blower. The walls of all of the functional parts described above which come into contact either with the exhaust media flow or with the ventilations media flow are constructed of highly heat-conducting, laminated material.
The primary disadvantage of this prior ventilation device lies in the fact that the two flows of media, the ventilation media flow and the exhaust media flow, have to be conducted over a relatively long distance past the contact surfaces of the heat exchanger in order to obtain the desired rate of heat recovery in an efficient manner.
This results in a relatively large total length of the boxed-shaped housing which contains the prior ventilation device because the inlet opening and the outlet opening for each of the ventilation flow routes and the exhaust media flow have a correspondingly large spacing from one another.
The primary object of the invention is to achieve an efficiency of heat recovery at least equal to or greater than a ventilation device as shown in German Patent 3,111,360 but with a substantially reduced total length and with no corresponding increase in depth.